When you run the Hybrid Configuration wizard even in a tenant that uses Federated login, you might find that even if you’ve chosen only one of your federated domains, the redirect URL to Office 365 is set to your tenant domain (onmicrosoft.com) rather than the federated domain you chose in the wizard or would prefer to use:
If you’ve not this before, this results in the end use having to enter their User Principal Name at the Microsoft Online Services login page, before being redirected back to the ADFS services:
So the first thing you might do is the following to set your TargetOWAURL to the correct value:
Set-OrganizationRelationship "On Premises to Exchange Online Organization Relationship" -TargetOwaURL:https://outlook.com/owa/federateddomain
This results in the smoother (or even super-smooth if you check out my previous article) experience where the end use is redirect straight to AD FS login.
If you need to update the Hybrid Configuration – for example to add or change IP addresses of External Transport Server IP addresses, update the certificate or add/remove Hub Transport or Client Access Servers, then you’ll re-run the Hybrid Configuration Wizard.
A seemingly innocuous change to an IP address for outbound SMTP servers that doesn’t affect the organization relationship itself will result in the Redirect URL for OWA being set back to the tenant domain resulting in the scenario outlined above.
So, just bear that in mind when you need to re-run the Hybrid Configuration wizard.. It’s simple to deal with by ensuring your reconfigure your TargetOWAURL, just make sure you don’t forget